Question

2g of lead nitrate powder is taken in a boiling tube. the boiling tube is heated over the flame. now answer the following:
1) state the colour of the fumes evolved and the residue left.
2) name the type of chemical reaction that has taken place stating its balanced chemical equation.

Answer 1

HERE IS YOUR ANSWER

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1) There are reddish brown vapours coming out.
The residue is black.

2) The chemical reaction is DECOMPOSITION REACTION.

2Pb(NO3)2 -----> 2PbO + 4NO2 + O2

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THANK YOU

Answer 2

Answer:

The color of fumes is Reddish-brown and residue left is lead oxide.

The chemical reaction is thermal decomposition.

Explanation:

• The color of lead nitrate before heating is white. But after heating of lead nitrate, its color changes from white to yellow  due to the formation of lead oxide. The colure of the fumes evolved will be Reddish-Brown due to the formation of nitrogen dioxide.
• The thermal decomposition reaction will take place on heating lead nitrate.
• on heating of lead nitrate, there is formation of oxygen gas, nitrogen dioxide gas and lead oxide (PbO).
• Representation of balanced chemical equation:

       $2Pb(NO_{3})_{2}$ (s)  $\longrightarrow \:2PbO$  + $4NO_{2}$ (g)  + $O_{2}$ (g)